CNC Maker Upgrades a Vintage Three-Axis Mill Into a Mach3-Controlled Four-Axis CNC Beast

Pseudonymous Macedonian CNC specialist CNC Maker has turned a vintage three-axis mill into a four-axis computer-controlled beast — retro-fitting it with the components required for control via Newfangled Solutions' Mach3 software.

"The [Stankoimport] 8H80G model [mill] is a high-precision milling machine that has been designed to provide excellent accuracy and repeatability," CNC Maker explains of the desire to re-use the vintage machine. "It features a robust construction, a decent bed size, and a powerful spindle that can easily handle tough materials like steel and aluminum.

"The spindle on the 8H80G model is a high-speed motor that can rotate at a maximum speed of 1439 rotations/minute, with a power rating of 3 kW and a current draw of 6.5A. This spindle operates at 380 volts and is designed to work on a 50Hz power supply."

Rather than using it manually, though, CNC Maker — as hinted by the name — sought to upgrade the system to computer numeric control along four axes. What followed was a days-long process of retro-fitting suitable electronics, custom-built replacement mechanical parts milled and laser-cut, new NEMA 23 stepper motors on 1:10 planetary gears, and more — plus some issues with a broken weld and bent shaft on the Z axis which needed to be resolved.

Once the X, Y, and Z axes had been upgraded, the machine was tested by getting it to draw a simple circle under computer control — but the idea was not only to convert the mill for CNC operation but to add a fourth axis too. More fabrication followed, including the addition of a 1:50 gear system and a chuck that could accept materials to be rotated.

The successful upgrade is visible in the above video or on the CNC Maker YouTube channel — though design files for the fabrication have not been made publicly available.